Re: Add generate_series(numeric, numeric)

On Sun, Oct 5, 2014 at 7:39 PM, Ali Akbar <the(dot)apaan(at)gmail(dot)com> wrote:

>
> 2014-10-05 15:21 GMT+07:00 Ali Akbar <the(dot)apaan(at)gmail(dot)com>:
>
>> - i think you can use the fctx->current variable without temporary
>> variable (there's comment in the add_var function: Full version of add
>> functionality on variable level (handling signs). result might point to one
>> of the operands too without danger.). But you _must_ switch the context
>> first because add_var will allocate new array for the data and freeing the
>> old one.
>>
> Yep.

> - numeric can be NaN. We must reject it as first, finish and last
>> parameter.
>>
> Makes sense.

> - numeric datatype is large, but there are limitations. According to doc,
>> the limit is: up to 131072 digits before the decimal point; up to 16383
>> digits after the decimal point. How can we check if the next step
>> overflows? As a comparison, in int.c, generate_series_step_int4 checks if
>> its overflows, and stop the next call by setting step to 0. Should we do
>> that?
>>
> Yes we should.

> - while testing regression test, opr_sanity checks that the
> generate_series_numeric function is used twice (once for 2 parameter and
> once for the 3 parameter function), so i changed the name to
> generate_series_step_numeric and created new function
> generate_series_numeric that calls generate_series_step_numeric.
>
Yep.

It seems to me that this patch is heading in a good direction (haven't
tested or tried to break it, just looked at the code). However please be
careful of code format, particularly brackets for "if" blocks. For example
this thing:
if (foo) {
blah;
}
Should be that:
if (foo)
blah;
Then in the case of multiple lines, this thing:
if (foo) {
blah;
blah2;
}
Should be that:
if (foo)
{
blah;
blah2;
}
Code convention is detailed in the docs:
http://www.postgresql.org/docs/devel/static/source.html
Regards,
--
Michael